The present invention relates to industrial process control or monitoring systems. More specifically, the present invention relates to systems which measure flow of process fluid in an industrial process.
Many industrial processes use or operate upon various types of fluids. During operation of the process, the fluids may be transferred through process piping from one location to another. In many instances, it is desirable to monitor the flow of such fluid through the process piping. The monitoring can be used for measurement purposes alone, or can be used in a control system. For example, a valve can be controlled based upon the amount of flow of process fluid which is measured.
Process variable transmitters are used to measure process variables of industrial processes. One such process variable is flow of process fluid is discussed above. Various techniques can be used to measure such flow. One such technique measures flow based upon a differential pressure developed across a restriction element placed in the process piping. The differential pressure can be measured by a differential pressure transmitter and used to calculate the flow of process fluid. The restriction element placed in the flow causes various pressures to be developed as described in WO2008/025935 entitled “IMPROVEMENTS IN OR RELATING TO FLOW METERING”, by Richard Steven having an international filing date of Aug. 29, 2006.